Neo Diagnostics ROMs

Razoola

Divine Hand of the UniBIOS,
Staff member
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Any ideas of the cause? BIOS itself works fine in other systems, so it's a failure in the MVS hardware. Just not sure where it is...

If your sure the EPROM is not failing then its either going to be the 68k or something interfering with the data lines. Do you have known working game carts. If so get to the UniBios main menu, hilight the game cart check then hold start and press the A button. This will test the bios again with a stronger check. See if it always passes or sometimes fails. Then do the same check with a game cart and see if that sometimes passes and then other times fails.
 

Kujako

Quiz Detective
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Posts
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If your sure the EPROM is not failing then its either going to be the 68k or something interfering with the data lines. Do you have known working game carts. If so get to the UniBios main menu, hilight the game cart check then hold start and press the A button. This will test the bios again with a stronger check. See if it always passes or sometimes fails. Then do the same check with a game cart and see if that sometimes passes and then other times fails.

Well that's just it, all carts work. I see this error about 75% of the time, but if I just hit <A> to resume, it carries on and everything works. Once I bypass the error, there is no sign that there's any problem. Unless I allow the hardware test to complete, then it's bricked. So to avoid that I have the battery pulled and UNIBIOS defaults to not running the tests.
 

Xian Xi

JammaNationX,
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Well that's just it, all carts work. I see this error about 75% of the time, but if I just hit <A> to resume, it carries on and everything works. Once I bypass the error, there is no sign that there's any problem. Unless I allow the hardware test to complete, then it's bricked. So to avoid that I have the battery pulled and UNIBIOS defaults to not running the tests.

He's not telling you to test the carts, the test he's telling you to do is to test the bios itself which uses the CRC check that is normally used for checking the game carts.
 

Kujako

Quiz Detective
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He's not telling you to test the carts, the test he's telling you to do is to test the bios itself which uses the CRC check that is normally used for checking the game carts.

Yes. And the BIOS works fine in other MVS boards. I have tested with UniBIOS 3.3 that I burned, UniBIOS 4 which I purchased, and and a backup copy of UniBIOS 4 that I burned. All work the same, failing at times in this system and working perfectly in others. Unfortunately, I do not have a copy of the original 1FZ BIOS or I would test with that as well. I had hopped that the NeoDiagnositcs BIOS and cart' would tell me something, but they say that everything is working... I THINK that the problem is with the watchdog timer. But at a loss as to how to confirm that.
 

Razoola

Divine Hand of the UniBIOS,
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You have not read properly my post properly and your also going off the premise that if the game looks to run fine then it runs fine. That is not a good way to check that faults of this nature. Read my post again and do the checks I suggest in the way I suggest using the gamecartcheck menu. Well unless your happy with the fault as it is now and simply skippig it every time it happens.
 

Kujako

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You have not read properly my post properly and your also going off the premise that if the game looks to run fine then it runs fine. That is not a good way to check that faults of this nature. Read my post again and do the checks I suggest in the way I suggest using the gamecartcheck menu. Well unless your happy with the fault as it is now and simply skippig it every time it happens.

You are correct, I missed your recommendation for a more detailed check of the BIOS. Will do so when I get the chance.
 

Xian Xi

JammaNationX,
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Check if the bios on the motherboard has 38,39 and 40 connected to +5v, if not, connect them. That sometimes helps.
 

Kujako

Quiz Detective
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Check if the bios on the motherboard has 38,39 and 40 connected to +5v, if not, connect them. That sometimes helps.

I shall add that to my to do list, which grows faster than it shrinks.

Back on topic, should I be able to use a neo diagnostics MVS cart on an AES with a converter? Don't have a spare AES cart to swap out the M1 chip on...
 

xterc

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neo-batteries.jpg

This batch of unfriendly venom spewing batteries has given me a headache recently, but nothing that can't be overcome. However, I do have a Z80 COMM issue that I can't seem to get to the bottom of on an MVS2F.

Using NEODIAG and the Z80 test cart, I get 'EXPECTED C3, ACTUAL 53' - Unexpected IRQ Error 13.

When booting the Z80 cart it plays the beeps during the NEO GEO splash screen and the built in ROM will plays the sound test OK. However, no sampled sounds are generated in-game.

Whenever a sound should be played SDW is pulsed, but NMI is not. I've replaced what seems like every chip (Z80, C1, D0, E0, YM2610, 6116)
this made a difference, but didn't fix the issue.

I've checked continuity between what seems like every trace.

Z80 D0..D7 -> NEO-C1 SD0..SD7
Z80 IORQ (20) -> NEO-D0 IORQ (37)
NEO-D0 SDZ80R (41), SDZ80W (43), NEO-C1 SDZ80R (84), SDZ80W (85)
68000 Data Lines -> NEO-C1 SD0~SD7

I'd like to say thank you to GadgetUK, SMKDan & Furrtek for all of the progress I've made on the other boards so far.

Is there any chance the firmware to NeoDIAG can be open sourced? I'd like to get an understanding as to exactly what is going on, so I can troubleshoot further.
 
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GadgetUK

Robert Garcia's Butler
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I was going to suggest the DAC, until I noticed your earlier point that its showing C3 vs 53 and an unexpected IRQ. Have you tried the SM1- or tried an SM1 bypass to rule it out at least.

EDIT: Also, is there by chance a G0 connected to that Z80 stuff on that board?
 
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xterc

Twinkle Star Sprite
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I've replaced the DAC, changed SM1, swapped an E0, G0, C1 & a 257. The Z80 and SM1 have been socketed.

The BIOS test sounds do play. I'm at a loss with this board.
 

xterc

Twinkle Star Sprite
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Jul 22, 2017
Posts
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Sound Restored

Never-mind I figured it out...

The HC259 addressable latch that drives the OE (output enable) of the NEO-257 needed replacing. It is located in a completely different part of the board than the rest of the Z80/YM stuff.

The NEO-GEO development Wiki helped again with the following statement 'Multiplexer slot selection from NEO-F0, /OE from NEO-D0 and OE from 74HC259 to NEO-257. The 257 must only output to Z80 when it is trying to read ROM (NEO-D0) and the cart M1/S1 is selected (74HC259).'

I've highlighted the reference chips in the attached image in case it helps anyone else out.

HC259-SOUND.jpg
 

Kujako

Quiz Detective
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Yup, seems to have worked. However it found no problems. Hurmph, guess I have to break out the logic probe and check traces.

Following up on this. Found no bad traces, but the 74HC32A seemed to have issues. Replaced the battery and the 74HC32A (took awhile to get the parts together) and that seems to have fixed the first round of problems (remembers dates etc now and doesn't need the battery disconnected). However, it still shows a hardware failure on boot with the UNIBIOS, listing nothing under -ADRS-, -HW- and -RE-. I tried running the Neo Diagnostics BIOS again (confirming that it works on another board) and I get no video signal.

So this is a change in behavior, in that I can no longer get the Neo Diagnostics BIOS to run.
 

ack

King's Dry Cleaner
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With smkdan having disappeared 5+ years ago, I am curious what folks would think about me releasing a disassembled version of the diag bios (sp1 + m1). I would like to make it available but it feels like a bit of a gray area since its not mine.

I did most of the disassembly a number of months ago as a way to learn 68k/z80 assembly, neo geo hardware and get to a better understanding of what some of the errors mean. Everything is fully disassembled, documented and compiles back to the same crcs as smkdan's released sp1/m1 files.
 

shadowkn55

Genbu's Turtle Keeper
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That's a tough call. But since he did release it as a free download as opposed to a paid product, I'm leaning towards releasing it because it would be a very helpful educational tool.
 

Xian Xi

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With smkdan having disappeared 5+ years ago, I am curious what folks would think about me releasing a disassembled version of the diag bios (sp1 + m1). I would like to make it available but it feels like a bit of a gray area since its not mine.

I did most of the disassembly a number of months ago as a way to learn 68k/z80 assembly, neo geo hardware and get to a better understanding of what some of the errors mean. Everything is fully disassembled, documented and compiles back to the same crcs as smkdan's released sp1/m1 files.

Last time I spoke to Dan he told me his plans for the Neo Diagnostics was to make a cart that would test the full system even full comm between different areas of the board. I'm not sure what happened to him as I've reached out multiple times, I hope nothing tragic as I was really looking forward to seeing it come to fruition.
 

lachlan

drunk downunder!, aka. Muff Diver.,
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I'm going to side with releasing what you have so that someone else can potentially take it over.
 
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ack

King's Dry Cleaner
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Posts
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Last time I spoke to Dan he told me his plans for the Neo Diagnostics was to make a cart that would test the full system even full comm between different areas of the board. I'm not sure what happened to him as I've reached out multiple times, I hope nothing tragic as I was really looking forward to seeing it come to fruition.

I hope hes ok too.

I have a few changes I would like to make, but nothing overly complex

- make it possible to go to the main menu after a successful automatic test
- make it possible to go to the main menu after a manual wram test
- print the slot number when doing the z80/m1 test
- fix z80 ram address test
- with some errors, make it possible to continually hit the effected address so you could to use a logic probe to try and hunt down the issue
 

Xian Xi

JammaNationX,
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One thing I wanted to ask Dan was, why isn't it possible to make color bars work on AES?
 

ack

King's Dry Cleaner
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Probably because of a lack of sfix.

Yeah, hes using 4 different tiles from sfix that are a solid color. Then using palettes to make them correct color/intensity when generating the color bars.

I will try and put up the disassembly tomorrow.
 

Xian Xi

JammaNationX,
Joined
Dec 1, 2005
Posts
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Yeah, hes using 4 different tiles from sfix that are a solid color. Then using palettes to make them correct color/intensity when generating the color bars.

I will try and put up the disassembly tomorrow.

Is there any work around to get it to work on AES like pull it from the cart inserted, kinda like how the Unibios does?
 
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